Chemical emergency valve



Nov. 27, 1962 J, DE FREES CHEMICAL EMERGENCY VALVE 2 Sheets-Sheet 1Filed Jan. 13, 1960 6 z J 3 4 0 2& w 8

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CHEMICAL EMERGENCY VALVE Filed Jan; 15, 1960 2 Sheets-Sheet 2LLl/l/l/ll/l'71 INVENTOR. Bu-p H Dc H556 WZZC/QMCWE United States Patent3,065,949 r CHEMICAL EMERGENCY VALVE Joseph H. De Frees, 414 LibertySt., Warren, Pa. Filed Jan. 13, 1960, Ser. No. 2,212 5 Claims. (Cl.25162) This invention relates to novel and improved valve structuresparticularly adapted for the control of liqui flow from stationary ormovable tanks or the like. One specific use for which I have found thevalve to be adapted is the control of discharge flow from single ormulti-compartment tank trucks or trailers which are used for gasoline oroil transportation and chemicals. Valves of this nature are termedemergency valves when, as is customary, they are provided with means forthe prevention of accidental or unintended discharge of flammable orexplosive contents, the valve being provided with means for positivelymaintaining the valve in closed position in case of fire, or an accident'which damages piping, such as roll over of the tank in a trafficaccident.

The Interstate Commerce Commission has established safety regulationsfor liquid discharge means on tanks which transport flammable orpoisonous liquids. It is required that each tank be equipped with anemergency valve provided with an automatic shut-off in 'case of fire;that the valve retain the'product in the tank in case of damage toexterior discharge piping; that the valve have a remote closing deviceif the usual shut-off control is engulfed in flames.

It has been found necessary to mainly within but partially without saidconduit.

3,065,949 Patented Nov. 27, 1962 pocket has a central aperture 11a, tothe periphery of which I attach an annular flange 12 by bolts 13 andnuts 14. A leakproof ring gasket 15 is compressed between flange 12 andthe drain pocket periphery.

The flange supports a conduit elbow 16 through which liquid isdischarged, the elbow having a connector flange 16a for attachmentthereto of further liquid-carrying piping.

A unit 17 comprising an emergency valve, and valve control means, iscarried on elbow 16 and is dispols id e conduit has a fitted aperture topermit outward extension of the lower end of the valve unit, tofacilitate connection to a fluid power source, as will appear.

To eliminate confusion in subsequent terminology, let

. me say that in conventional usage, in a cylinder-piston cooperatingassembly in which there is relative movement between piston andcylinder, the piston is the moving element. This of course is notnecessarily so, but the usual procedure is here mentioned since indescribing the present valve control unit I will term a fixed member thepiston, and a movable member the cylinder, both these members arelocated co-axially within a cylindrical housing whereby to simplify thecleaning problem'as aforesaid.

. The unit 17 will now be more specifically described.

It comprises a housing 20 fixed in leakproof fashion in 'the aperture inthe wall of conduit elbow 16, being retained by welding 21 around theaperture edge. The inner upper end of the housing 20 is positioned andretained by spider legs 22 within the upper part of the elbow.

A piston 23 has an enlarged end portion 23a screwthreaded to a secureattachment to the lower end of housing 20. A cylinder 24 is slidablycarried on the elongated shank of piston 23, and the cylinder at itsupper end has 7 a screw-threaded connection to a valve head disc 25Previous emergency valves have presented an almost 7" impossiblesituation from a cleaning standpoint with their exposed springs, cages,and bonncts, etc.

An object of the present invention is to provide a novel emergency valvestructure which permits great simplification in the cleaning operation.

A further object of the invention is to provide an emergency valvestructure in which practically all the working parts are enclosed, so asto be out of contact with the liquid being charged, carried ordischarged.

A further object of the invention is to provide an emergency valvestructure which completely protects the liquid load from contact orcontamination with leakage from the valve operating pressure fluid.

Other objects and advantages will be apparent from a study of thefollowing description of several embodiments of the invention, inconjunction with the following drawings, in which:

FIG. 1 is a vertical sectional view taken axially through an emergencyvalve structure constructed in accordance with the present invention.

FIGS. 2 and 3 are horizontal sectional views taken respectively on thelines 22 and 33 of FIG. 1.

FIG. 4 is an elevational view, partly broken away and in section,showing anothe adaptation of the invention.

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4.

The drawings show a fragmentary portion 10 of the bottom wall of aliquid transportation tank. The wall 10 has a downturned flange 10awhich is welded to a sheet metal sump 11 constituting a drain pocket.The drain which is downwardly seatable on the peripheral edge of flange12. This valve disc is perforated and threaded to receive a bleed plug26 for a purpose to hereinafter appear.

Cylinder 24 carries on its lower outer end a springbacking nut or washer27 which has a snug sliding fi-t within housing 20 and serves as an endabutment for a compression spring 28. The upper end of spring 28 abutsagainst a rabbeted washer 29 which seats on' an inner shoulder ofhousing 20. a

The normal tendency of spring 28 is to bias cylinder 24 and valve head25 downwardly so that the valve head seats in sealing relationshipagainst flange 12 so as to prevent discharge of liquid from the tank.

The sliding relationship between the piston 23 and the cylinder 24 isrendered leakproof by packing 32 retained and compressed by a packingnut 33. Around its outer face the cylinder is sealed by packing 34backed up by a packing gland 35 and a compression spring 36 which has arear abutment against the washer 29 previously mentioned.

Hydraulic pressure fluid through a pipe 37 can be supplied through abored plug fitting 38 and through an axial bored passage 39 in piston 23so as to enter cylinder head 40. Bleed plug 26 may be removed to permitescape of all air, and is replaced as soon as the pressure fluid reachesthe plug aperture. This needs to be done only once, when initiating useof this particular valve control.

In operation the procedure is as follows. When it becomes desirable todischarge liquid from the tank any suitable hydraulic fluid isintroduced through pipe 37 into bore 39 and pressure head 40, therebyraising valve disc 25 against the bias of spring 28. The liquid contentsare then discharged through elbow 16. Closure of the valve disc 25 iseffected by terminating hydraulic pressure at a manual control point bymeans of an inletexhaust type of valve (not shown) which permits spring28 to expand, reducing the volume of the pressure head and forcing thehydraulic fluid backwardly to the exhaust point.

' A shear zone, consisting of an annular groove 43 to reduce the wallthickness, is provided so that understructure may readily tear off incase of accident. Even on an assumption that the accident will damagethe valve control unit 17, the valve disc 25 will be maintained inclosed position, as long as the tank remains upright, by gravitypressure. If gravity pressure is not eflective because the tank rollsupside down, then the liquid will not flow out because the aperture isuppermost.

FIGS. 4 and 5 show an adaptation of the invention to a T outlet from aliquid transportation or storage tank. In this arrangement the unitgenerally designated as 17a is fixed in the bottom wall 45a of theconduit T section 45 and is welded all around at 46, inside and outside.The piston 47, cylinder 48 and valve disc 49 are all similar to thecorresponding elements in FIGS. 1-3.

The invention of course is susceptible to the various desirablesafeguards which have been developed by experience. The hydraulic fluidline 37 may have, in spur connection thereto, a low-melting point plugwhich melts and vents the pressure upon development of dangerously hightemperatures near the tank. A remote control vent valve may be providedfor instantaneous manual operation in case of a fire which preventsaccess to the usual emergency valve controls.

The present arrangement is such that should any leakage of hydraulicfluid occur past packing 32 it will be discharged through weep holes 50(FIG. 1)'rather than into the zone of discharge of product liquid flow.Should any leakage of the product liquid occur past packing 34 anddownwardly, it will also be discharged through weep holes 50.

What is claimed is:

1. Tank discharge means for a liquid-containing tank having a bottomwall, a discharge port in said bottom wall, and a discharge pipe in flowcommunication with said port and leading away from said tank, saiddischarge means including a valve and a valve operating unit, said valvebeing seatable in sealing relationship in said port and said operatingunit including an imperforate shell completely outside and below saidbottom wall and extending through the wall of said discharge pipe andhaving a portion outside said wall, and a portion within said dischargepipe in registry with said port, said operating unit further including acylinder-piston co-operating couple within said shell, said cylinderhaving a power head chamber enlargeable and contractable by relativemove ment between said cylinder and said piston, the movable member ofsaid couple being extendable out of said shell towards said port, andmeans operatively uniting said valve and said movable member whereby toopen said valve when fluid power is admitted to said power head chamber.

2. Tank discharge means as defined in claim 1 wherein said cylinder isthe movable member, and said piston has an axial bore therethroughthrough which bore said fluid power is admitted to said power headchamber.

3. Tank discharge means as defined in claim 2 wherein biasing means isprovided to return said cylinder to valveclosed position upon cuttingoff fluid power to said power head chamber.

4. Tank discharge means for a liquid-containing tank having a bottomwall, and a discharge port in said bottom wall, said discharge meansincluding a valve and valve operating means, said valve being seatablein said port and said valve operating means depending outwardly fromsaid port and comprising a cylindrical body having a peripheral housingshell completely outside and below said bottom wall, and a piston withinsaid shell, the shell and piston being coaxial but providing an annularspace therebetween, means for closing said space at the outer ends ofsaid shell and piston, a tubular cylinder disposed coaxially with saidpiston and said shell in said annular space and being slidable on saidpiston, the inner end of said cylinder being closed, means for admittingpressure fluid to said cylinder whereby to produce relative movementbetween said cylinder and said piston, means establishing an operativeconnection between said valve and the power unit consisting of saidcylinder and said piston whereby such relative movement moves said valvetowards or from sealing position.

5. Discharge means of the type defined in claim 4 wherein the means foradmitting pressure fluid to said cylinder includes an axial bore in saidpiston through which the pressure fluid enters to contact the inner endof said cylinder.

References (lited in the file of this patent UNITED STATES PATENTS2,019,786 Jurs Nov. 5, 1935 2,726,840 Jurs et al. Dec. 13, 19552,859,765 Streed Nov. 11, 1958 2,973,009 Kazyaka Feb. 28, 1961

